from the sweet-pea.”

In the garden the sweet-peas were really lovely. They looked, as Frank said, like so many beautiful butterflies on the wing; and they filled the air with delicious perfume.

“I think,” said Frank, “that our row of sweet-peas is by far the best thing in the garden.”

“That is quite true, Frank,” said his uncle, “but it is not so much the flowers we are going to study at present. The sweet-pea is certainly one of our finest flowering plants. It is also one of the most interesting. Can you tell me why we put stakes up for our sweet-pea plants to cling to?”

“Because they have long, slender stems—too slender and weak to grow up by themselves,” said Frank.

“Quite right, Frank. If the sweet-pea were a wild plant, where would it grow?”

“In the hedges,” said Tom.

“Right again,” said Uncle George. “If we grow the sweet-pea in the garden, we must imitate its surroundings in the wild state—we must give it a hedge of some kind to cling to, otherwise it would trail along the ground.”

“Then it would get choked among the other plants,” said Frank.

Rose Leaf.

Vetch Leaf.

Ash Leaf.

“What do you mean by ‘choked,’ Frank?”

“Well, it would die for want of air”——

“And light,” his uncle added. “No green plant can live without air and sunlight; and, in order to get these, our weak-stemmed sweet-pea has to climb. It clings to its stronger brethren just as the wild peas do in the hedgerow. Now notice how it climbs. The end part of each leaf consists of little gripping organs called tendrils. These twine tightly round the smallest twigs near them.

1. Ox Eye.

2. Daisy.

3. Corn Marigold.

“Here is a rose leaf. It is composed of several leaflets, and at its base there are two small, brownish-green things called stipules. If we compare this leaf with the leaf of the sweet-pea, we find that in some points they are similar, but in others very different.

Sweet-Pea.

Edible Pea.

“The rose leaf is called a compound leaf, because it is made up of many small leaflets. The sweet-pea leaf is also a compound leaf, but it has only two leaflets, and these are of enormous size. The rose leaf has two small stipules. The stipules of the sweet-pea leaf are large and green.

“If I place the rose leaf beside a sweet-pea leaf, you will notice that the latter has no upper leaflets.”

“It has tendrils ‘instead,’” said Frank.

“Exactly!” said Uncle George. “These tendrils correspond to leaflets. Now, if the plant has been forced to turn all its leaflets, except two, into gripping organs, how does it manage to make up for this loss of green leaves?